Fulton had it all going for him back then and much of the confidence he would later lose. A fit n' focused Fulton should get the measure of Firpo and beat him to the floor within 5 rounds. Firpo can land the big one, but that should be a less likely scenario.
Good fight. Honestly, I think Firpo's awkward style could give a text-book, stand up boxer like Fulton fits, and Firpo's power would find Fulton's weak chin eventually. Firpo might blow Fulton out if he lands a lucky punch, but I figure Fulton would out-box him for a while before getting sparked in the mid rounds. If it goes to a decision, Fulton might take it, but I think, more than likely, Firpo wins by KO. Or maybe I'm totally wrong. Maybe Fulton schools Firpo all night long and grinds him down for a late stoppage of his own. Who knows? Wizards, maybe, but not me.
Hard to pick because there's nothing on film of Fulton, but he had a very weak jaw and i'd pick Firpo, wild an unskilled as he is, to find it sooner or later and win by knockout.
Hard to say. I'd learn to Firpo breaking though and scoring a stoppage win. Fulton might have been an ok boxer, but I have read he was a bit stiff...AKA not great on defense.